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20031121: LDM and viability of multiple instances of pqact

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  • Subject: 20031121: LDM and viability of multiple instances of pqact
  • Date: Fri, 21 Nov 2003 14:32:40 -0700
Art,

When pqact starts up, it is looking at the end of the product queue
(unless the -o option is used). So, if you restart the LDM, and
pqact had fallen behind in its processing of the queue, you would lose
that state information on restart- eg, your pqact output would be skipping
those products bewteen where it was when it was shut down and where
the end of the queue is when it restarts. This would happen 
anytime pqact was behind on processing (single or multiple pqact instances).

I'll CC Steve Emmerson in case he has a different view.

Steve Chiswell





>From: "Arthur A. Person" <address@hidden>
>Organization: UCAR/Unidata
>Keywords: 200311212055.hALKtBEH026237

>Hi...
>
>I've been wondering lately about the LDM and whether running multiple
>instances of pqact is an allowable option.  I have several instances of
>pqact running on a particular machine, each using a different
>configuration file.  I originally did this back when data got bogged down
>on the internet (which it doesn't seem to do anymore) so that if one
>stream of data got behind, other lower-volume streams wouldn't get behind
>also when processed by a single, serial, pqact instance (e.g. CONDUIT vs.  
>DDPLUS).  However, I've been wondering what happens if I stop and restart
>the LDM in this case...  does the LDM remember where each of these pqact
>instances left off in the input queue, or does it only remember where one
>of them left off, in which case, data could potentially be lost.  Could
>you enlighten me?
>
>                                 Thanks.
>
>                                   Art.
>-- 
>Arthur A. Person
>Research Assistant, System Administrator
>Penn State Department of Meteorology
>email:  address@hidden, phone:  814-863-1563
>